Telegraph Creek Headwaters 



Climatic setting. The net annual precipitation balance for the 

 Telegraph Creek Headwaters (from the MAPS database) is -3 inches, 

 placing the site near the humid end of the range shown by the 

 sample sites, but mid-range for those in the Rocky Mountains. Mean 

 monthly precipitation for the Basin climatic station (at a much 

 different elevation than the site) shows a bimodal distribution, 

 with a primary June maximum and a secondary January peak. The 

 three-year running average of annual precipitation for the Boulder 

 station (also at some distance from WET66) shows values below the 

 long-term average for much of the 1980s and near or above the long- 

 term average for 1990-93, with precipitation in 1993 (the year of 

 sampling) almost 6 inches above average. [Water supply to the 

 Telegraph Creek headwaters is probably supported mainly by winter 

 snowpack, however, which is not reflected in data from these low- 

 elevation stations.] 



Geologic setting. The Telegraph Creek wetland is underlain by 

 deeply weathered glacial till interpreted as early Wisconsin in 

 age. Glacial deposits, which are probably very thin, overlie the 

 Cretaceous-aged Elkhorn volcanics and guartz monzonite the Boulder 

 batholith. Hydrothermal mineralization has encouraged extensive 

 prospecting and historic ore production at numerous nearby sites 

 along the Ontario Creek-Telegraph Creek divide. 



Hydrologic type. WET66 is a small headwaters site with 

 intermittent(?) surface water outflow and without channelized 

 inflow. Although ground-water relationships are not known, the 

 position of the wetland near a drainage divide suggests recharge 

 from the wetland to ground-water may occur. 



Basin characteristics. The Telegraph Creek wetland is a shallow 

 basin with a small, low-gradient catchment and a low catchment to 

 wetland area ratio in comparison to other Rocky Mountain sampling 

 sites. No mines or prospects are known within the immediate 

 catchment, but some level of sulfide mineralization is probably 

 ubiguitous in the area. 



Water chemistry. The Telegraph Creek wetland is characterized by 

 dilute, mildly acidic calcium-bicarbonate/sulf ate water distinctly 

 different in major-ion chemistry from that of the nearby Ontario 

 Creek Headwaters site (WET58). The dissolved solids concentration 

 and pH are considerably higher at the Telegraph Creek site, and the 

 sulfate concentration proportionately much lower. Ammonium and 

 phosphorous concentrations are also higher at WET66, with the 

 orthophosphate concentration ranking toward the upper end of the 

 range shown by Rocky Mountain sites. 



The arsenic, boron, copper, iron and lead concentrations in the 

 WET66 sample were all relatively high, exceeded in the Rocky 

 Mountain sites mainly by sites with known mining and mineral 

 processing impacts. Other trace elements analyzed were below 



